Knee Orthopaedic Test: Renne Test

Renne's test is a physical examination technique used to assess for patellar instability in the knee joint. Here are the steps to perform Renne's test:

1. Have the patient lie down on their back on the examination table with their legs straight.
2. Flex the patient's affected knee to 20-30 degrees.
3. Place one hand on the patient's patella and the other hand on the patient's ankle.
4. Apply a lateral force to the patella, or push the patella laterally.
5. Ask the patient to contract their quadriceps muscle, as if they were trying to straighten their knee.
6. Observe the patient's patella for any signs of lateral displacement or instability.

If the patient's patella moves laterally or becomes unstable during quadriceps contraction, this may indicate patellar instability. However, it is important to note that Renne's test should be used in conjunction with other examination techniques and diagnostic tests to accurately diagnose knee injuries. 

References:

1. Renne, J. W. (1980). The use of the patellar apprehension test in the management of patellar dislocation. The American journal of sports medicine, 8(3), 151-154.

2. Magee, D. J. (2014). Orthopedic physical assessment. Elsevier Health Sciences.